Experiment #4: Just a Bag of Hot Air

You can fill out this Lab Sheet on the computer and send it to your teacher's email address by clicking on the submit button when you are finished. Or click on this version, print it out, and fill it in by hand.

Question: How can you inflate a balloon without blowing into it?

In this activity you will be using three simple materials to inflate a balloon without actually blowing into it. Your task is to figure out how to do this and then to explain why your experiment worked (i.e. what caused the balloon to inflate even though no new air was pumped into it).

You will need
   for each group:

  • a balloon
  • a narrow-necked bottle
  • a pan of hot water
  • 1 Lab Sheet
    1. Devise a way to inflate your balloon with the given materials.
    2. Record your plan in the hypothesis section of the Lab Sheet. (We will inflate the balloon by......)
    3. Record the steps of your procedure and your observations onto the Lab Sheet.
    Did your experiment work?
    If not, devise another way to inflate your balloon. If you succeeded in inflating the balloon, go to Hypothesis Revisited and explain what you think caused your balloon to inflate.

    Class Discussion

    Following the class discussion, your group should reassemble and decide upon your concluding hypothesis (i.e. how to inflate the balloon with the given materials and why this worked)

    [Live from Earth & Mars]__________________________________________________